1. Field
The present disclosure relates generally to telecommunications, and more particularly, to systems and methods for controlling and managing access to a wireless network.
2. Background
The demand for wireless information services has led to the development of an ever increasing number of wireless networks. CDMA2000 1x is just one example of a wireless network that provides wide area telephony and data services. CDMA2000 1x is a wireless standard promulgated by the Third Generation Partnership Project 2 (3GPP2) using code division multiple access (CDMA) technology. CDMA is a technology that allows multiple users to share a common communications medium using spread-spectrum processing. A competing wireless network that is commonly employed in Europe is Global System for Mobile Communications (GSM). Unlike CDMA2000 1x, GSM uses narrowband time division multiple access (TDMA) to support wireless telephony and data services. Some other wireless networks include General Packet Radio Service (GPRS) which supports high speed data services with data rates suitable for e-mail and web browsing applications, and Universal Mobile Telecommunications System (UMTS) which can deliver broadband voice and data for audio and video applications.
These wireless networks can generally be thought of as wide area networks employing cellular technology. Cellular technology is based on a topology in which the geographic coverage region is broken up into cells. Within each of these cells is a fixed base transceiver station (BTS) that communicates with mobile users. A base station controller (BSC) is typically employed in the geographic coverage region to control the BTSs and route communications to the appropriate gateways for the various packet-switched and circuit-switched networks.
As the demand for wireless information services continue to increase, mobile devices are evolving to support integrated voice, data, and streaming media while providing seamless network coverage between wide area cellular networks and wireless local area networks (LAN). Wireless LANs generally provide telephony and data services over relatively small geographic regions using a standard protocol, such as IEEE 802.11, Bluetooth, or the like. The existence of wireless LANs provides a unique opportunity to increase user capacity in a wide area cellular network by extending cellular communications to the unlicensed spectrum using the infrastructure of the wireless LAN.
However, unlike cellular services, many wireless LAN technologies allow all potential transmitting devices random access to the broadcast medium without guaranteeing particular Quality of Service (QoS) levels. Thus, for certain applications such as Voice over IP (VoIP), delays may be introduced between communicating users that are, at the least, minor annoyances and, at the worst, unacceptable from the user's viewpoint. Because many such wireless LANs also employ random back-off algorithms to avoid subsequent contention between the users, these delays (and therefore performance) only worsen as more VoIP users associate with a particular wireless LAN.
Some techniques for addressing this problem have been developed in the past with respect to 802.11 wireless LANs. These techniques have typically included assigning a priority to VoIP traffic and then handling that traffic outside of the implemented standard using tactics such as modifying the contention window, modifying the interframe spacing, jamming or overriding other traffic; not requiring an acknowledgement (ACK), using a zero-back-off setting, and transmitting VoIP packets ahead of any data packets waiting in the transmission queue.
Regardless of the merits of any of these techniques, continued improvement in the QoS of VOIP applications within a wireless LAN remains desirable and it is preferable that such improvement be accomplished without deviating from already established communications standards such as, for example, 802.11.